|
import os |
|
from pathlib import Path |
|
from typing import Any, Callable, Dict, List, Optional, Tuple, Union |
|
|
|
from torch import Tensor |
|
|
|
from .folder import find_classes, make_dataset |
|
from .video_utils import VideoClips |
|
from .vision import VisionDataset |
|
|
|
|
|
class UCF101(VisionDataset): |
|
""" |
|
`UCF101 <https://www.crcv.ucf.edu/data/UCF101.php>`_ dataset. |
|
|
|
UCF101 is an action recognition video dataset. |
|
This dataset consider every video as a collection of video clips of fixed size, specified |
|
by ``frames_per_clip``, where the step in frames between each clip is given by |
|
``step_between_clips``. The dataset itself can be downloaded from the dataset website; |
|
annotations that ``annotation_path`` should be pointing to can be downloaded from `here |
|
<https://www.crcv.ucf.edu/data/UCF101/UCF101TrainTestSplits-RecognitionTask.zip>`_. |
|
|
|
To give an example, for 2 videos with 10 and 15 frames respectively, if ``frames_per_clip=5`` |
|
and ``step_between_clips=5``, the dataset size will be (2 + 3) = 5, where the first two |
|
elements will come from video 1, and the next three elements from video 2. |
|
Note that we drop clips which do not have exactly ``frames_per_clip`` elements, so not all |
|
frames in a video might be present. |
|
|
|
Internally, it uses a VideoClips object to handle clip creation. |
|
|
|
Args: |
|
root (str or ``pathlib.Path``): Root directory of the UCF101 Dataset. |
|
annotation_path (str): path to the folder containing the split files; |
|
see docstring above for download instructions of these files |
|
frames_per_clip (int): number of frames in a clip. |
|
step_between_clips (int, optional): number of frames between each clip. |
|
fold (int, optional): which fold to use. Should be between 1 and 3. |
|
train (bool, optional): if ``True``, creates a dataset from the train split, |
|
otherwise from the ``test`` split. |
|
transform (callable, optional): A function/transform that takes in a TxHxWxC video |
|
and returns a transformed version. |
|
output_format (str, optional): The format of the output video tensors (before transforms). |
|
Can be either "THWC" (default) or "TCHW". |
|
|
|
Returns: |
|
tuple: A 3-tuple with the following entries: |
|
|
|
- video (Tensor[T, H, W, C] or Tensor[T, C, H, W]): The `T` video frames |
|
- audio(Tensor[K, L]): the audio frames, where `K` is the number of channels |
|
and `L` is the number of points |
|
- label (int): class of the video clip |
|
""" |
|
|
|
def __init__( |
|
self, |
|
root: Union[str, Path], |
|
annotation_path: str, |
|
frames_per_clip: int, |
|
step_between_clips: int = 1, |
|
frame_rate: Optional[int] = None, |
|
fold: int = 1, |
|
train: bool = True, |
|
transform: Optional[Callable] = None, |
|
_precomputed_metadata: Optional[Dict[str, Any]] = None, |
|
num_workers: int = 1, |
|
_video_width: int = 0, |
|
_video_height: int = 0, |
|
_video_min_dimension: int = 0, |
|
_audio_samples: int = 0, |
|
output_format: str = "THWC", |
|
) -> None: |
|
super().__init__(root) |
|
if not 1 <= fold <= 3: |
|
raise ValueError(f"fold should be between 1 and 3, got {fold}") |
|
|
|
extensions = ("avi",) |
|
self.fold = fold |
|
self.train = train |
|
|
|
self.classes, class_to_idx = find_classes(self.root) |
|
self.samples = make_dataset(self.root, class_to_idx, extensions, is_valid_file=None) |
|
video_list = [x[0] for x in self.samples] |
|
video_clips = VideoClips( |
|
video_list, |
|
frames_per_clip, |
|
step_between_clips, |
|
frame_rate, |
|
_precomputed_metadata, |
|
num_workers=num_workers, |
|
_video_width=_video_width, |
|
_video_height=_video_height, |
|
_video_min_dimension=_video_min_dimension, |
|
_audio_samples=_audio_samples, |
|
output_format=output_format, |
|
) |
|
|
|
|
|
|
|
self.full_video_clips = video_clips |
|
self.indices = self._select_fold(video_list, annotation_path, fold, train) |
|
self.video_clips = video_clips.subset(self.indices) |
|
self.transform = transform |
|
|
|
@property |
|
def metadata(self) -> Dict[str, Any]: |
|
return self.full_video_clips.metadata |
|
|
|
def _select_fold(self, video_list: List[str], annotation_path: str, fold: int, train: bool) -> List[int]: |
|
name = "train" if train else "test" |
|
name = f"{name}list{fold:02d}.txt" |
|
f = os.path.join(annotation_path, name) |
|
selected_files = set() |
|
with open(f) as fid: |
|
data = fid.readlines() |
|
data = [x.strip().split(" ")[0] for x in data] |
|
data = [os.path.join(self.root, *x.split("/")) for x in data] |
|
selected_files.update(data) |
|
indices = [i for i in range(len(video_list)) if video_list[i] in selected_files] |
|
return indices |
|
|
|
def __len__(self) -> int: |
|
return self.video_clips.num_clips() |
|
|
|
def __getitem__(self, idx: int) -> Tuple[Tensor, Tensor, int]: |
|
video, audio, info, video_idx = self.video_clips.get_clip(idx) |
|
label = self.samples[self.indices[video_idx]][1] |
|
|
|
if self.transform is not None: |
|
video = self.transform(video) |
|
|
|
return video, audio, label |
|
|